High-Entropy Configuration Strategy to Build High Performance Na-Ion Layered Oxide Cathodes Derived from Simple Techniques.

Layered transition metal oxides are commonly used as the cathode materials in sodium-ion batteries due to their low cost and easy manufacturing. However, the application is hindered by poor rate performance and complex phase transitions. To address these challenges, a new seven-component high-entropy layered oxide cathode material, O3-NaNi0.25Fe0.15Mn0.3Ti0.1Sn0.05Co0.05Li0.1O2 (HEO) has been developed. The entropy stabilization effect plays a crucial role in improving the performance of electrochemical systems and the stability of structures. The HEO exhibits a specific discharge capacity of 154.1 mA h g-1 at 0.1 C and 94.5 mA h g-1 at 7 C. In-situ and ex-situ XRD results demonstrate that the HEO effectively retards complex phase transitions. This work provides a high-entropy design for the storage materials with a high energy density. Meanwhile, it eliminates industry doubts about the performance of sodium ion layered oxide cathode materials.

Preoxidation and Prilling Combined with Doping Strategy to Build High-Performance Recycling Spent LiFePO4 Materials.

Direct regeneration has gained much attention in LiFePO4 battery recycling due to its simplicity, ecofriendliness, and cost savings. However, the excess carbon residues from binder decomposition, conductive carbon, and coated carbon in spent LiFePO4 impair electrochemical performance of direct regenerated LiFePO4. Herein, we report a preoxidation and prilling collaborative doping strategy to restore spent LiFePO4 by direct regeneration. The excess carbon is effectively removed by preoxidation. At the same time, prilling not only reduces the size of the primary particles and shortens the diffusion distance of Li+ but also improves the tap density of the regenerated materials. Besides, the Li+ transmission of the regenerated LiFePO4 is further improved by Ti4+ doping. Compared with commercial LiFePO4, it has excellent low-temperature performance. The collaborative strategy provides a new insight into regenerating high-performance spent LiFePO4.

Human induced pluripotent stem cell-derived planar neural organoids assembled on synthetic hydrogels.

The tailorable properties of synthetic polyethylene glycol (PEG) hydrogels make them an attractive substrate for human organoid assembly. Here, we formed human neural organoids from iPSC-derived progenitor cells in two distinct formats: (i) cells seeded on a Matrigel surface; and (ii) cells seeded on a synthetic PEG hydrogel surface. Tissue assembly on synthetic PEG hydrogels resulted in three dimensional (3D) planar neural organoids with greater neuronal diversity, greater expression of neurovascular and neuroinflammatory genes, and reduced variability when compared with tissues assembled upon Matrigel. Further, our 3D human tissue assembly approach occurred in an open cell culture format and created a tissue that was sufficiently translucent to allow for continuous imaging. Planar neural organoids formed on PEG hydrogels also showed higher expression of neural, vascular, and neuroinflammatory genes when compared to traditional brain organoids grown in Matrigel suspensions. Further, planar neural organoids contained functional microglia that responded to pro-inflammatory stimuli, and were responsive to anti-inflammatory drugs. These results demonstrate that the PEG hydrogel neural organoids can be used as a physiologically relevant in vitro model of neuro-inflammation.

Construction of Co1-x S Nanoparticles Embedding in N-Doped Amorphous Carbon@Graphene with Enhanced Li-Ion Storage.

Cobalt sulfide is deemed a promising anode material, owing to its high theoretical capacity (630 mAh g-1 ). Due to its low conductivity, fast energy decay, and the huge volume change during the lithiation process limits its practical application. In this work, a simple and large-scale method are developed to prepare Co1-x S nanoparticles embedding in N-doped carbon/graphene (CSCG). At a current density of 0.2 C, the reversible discharge capacity of CSCG maintains 937 mAh g-1 after 200 cycles. The discharge capacity of CSCG maintains at 596 mAh g-1 after 500 cycles at the high current density of 2.0 C. The excellent performance of CSCG is due to its unique structural features. The addition of rGO buffered volume changes while preventing Co1-x S from crushing/aggregating during the cycle, resulting in multiplier charge-discharge and long cycle life. The N-doped carbon provides a simple and easy way to achieve excellent performance in practical applications. Combined with density functional theory calculation, the presence of Co-vacancies(Co1-x ) increases more active site. Moreover, N-doping carbon is beneficial to the improve adsorption energy. This work presents a simple and effective structural engineering strategy and also provides a new idea to improve the performance of Li-ion batteries.

Construction of a Preoxidation and Cation Doping Regeneration Strategy to Improve Rate Performance Recycling Spent LiFePO4 Materials.

Efficient recycling of spent lithium-ion batteries (LIBs) is significant for solving environmental problems and promoting resource conservation. Economical recycling of LiFePO4 (LFP) batteries is extremely challenging due to the inexpensive production of LFP. Herein, we report a preoxidation combine with cation doping regeneration strategy to regenerate spent LiFePO4 (SLFP) with severely deteriorated. The binder, conductive agent, and residual carbon in SLFP are effectively removed through preoxidation treatment, which lays the foundation for the uniform and stable regeneration of LFP. Mg2+ doping is adopted to promote the diffusion efficiency of lithium ions, reduces the charge-transfer impedance, and further improves the electrochemical performance of the regenerated LFP. The discharge capacity of SLFP with severe deterioration recovers successfully from 43.2 to 136.9 mA h g-1 at 0.5 C. Compared with traditional methods, this technology is simple, economical, and environment-friendly. It provided an efficient way for recycling SLFP materials.

Synthesis of CoP@B,N,P co-doped porous carbon by a supramolecular gel self-assembly method for lithium-sulfur battery separator modification.

Lithium-sulfur batteries (LSBs) are regarded as promising next-generation batteries due to their high abundance and high theoretical energy density. However, the commercial application of LSBs is hindered by the shuttle effect of soluble lithium polysulfides (LiPSs). Hence, we synthesised B, N, P co-doped three-dimensional hierarchical porous carbon materials, uniformly dispersed with CoP nanoparticles, and utilized them as the coating material for the PE separator. The catalytic and adsorption capacity of the composite material was significantly enhanced by CoP. Both experimental and theoretical calculations show that the LiPS adsorption capacity of the composite material is significantly enhanced after the introduction of B atoms. As a result, the assembled LSBs with the CoP@BNPC/PE separator show excellent long-term stability (940.8 mA h g-1 after 500 cycles at 1.0 C, and only a 0.026% decay rate per cycle) and superior rate performance (613.6 mA h g-1 at 5.0 C). Our work further proves that a modified separator is an effective strategy to promote the commercialization of LSBs.

Effect of Initial Surface Scratches on the Cavitation Erosion Behavior of 316L Stainless Steel Substrates and 316L Stainless Steel Coatings.

Rough surfaces have been widely considered as negative factors affecting cavitation erosion resistance. However, this study presented the opposite result. Here, 316L stainless steel substrates and the arc-sprayed 316L stainless steel coatings were subjected to a specific grinding process that introduced scratches on the surfaces. The surface hardness values of these ground specimens were measured to evaluate the influence of the grinding-induced strain hardening. The cavitation erosion performance of the specimens was evaluated. The results showed that rough surfaces with scratches could enhance the cavitation erosion resistance, particularly at the early stage of cavitation erosion. The scratches had a greater effect on the cavitation erosion resistance of the coatings than on the substrates. Moreover, rough surfaces with initial surface scratches could extend the incubation period of the 316L stainless steel substrates due to the inhibition of the plastic deformation. The SEM observation showed that the scratch structure of the coating surface inhibited the growth of cracks and the propagation of cavitation pits. This study could also serve as a reference for investigating the cavitation erosion behaviors of materials with a particular surface feature.

Rational Design of a Robust Flexible Triblock Polyurea Copolymer Protective Layer for High-Performance Lithium Metal Batteries.

Dendrite growth and volume expansion in lithium metal are the most important obstacles affecting the actual applications of lithium metal batteries. Herein, we design a robust flexible artificial solid electrolyte interphase layer based on a triblock copolymer polyurea film, which promotes uniform lithium deposition on the surface of the lithium metal electrode and has a high lithium-ion transference number. The high elasticity and close contact of polyurea compounds effectively suppress lithium dendrite growth and volume expansion in the Li anode, which are effectively confirmed by electrochemical characterization and optical microscopy observation. The symmetrical batteries with the PU-Li metal anode can achieve stable and reversible Li plating/stripping over 500 h at a current density of 5 mA cm-2. Matched with the high-mass-loaded S cathode and the commercial NCM523 cathode, this film significantly improves the cycle life of lithium metal batteries.

Tuning Electrochemical Performance of Li-Rich Layered Cathode Materials with a Solid Phase Fusion Strategy.

Li-rich layered cathode materials (LRMs) have attracted extensive attention because of their high theoretical specific capacity. However, their practical application is limited by the severe depreciation of capacity and voltage during cycling. Herein, high electrical conductivity MoS2 is constructed on Li1.2Ni0.2Mn0.6O2 (LLNM) surface through solid phase fusion technology (SFT). Extraordinarily, the MoS2 modified layer lessens the interface side reaction and stabilizes the surface structure of LLNM. Meanwhile, the strong electron conductivity of MoS2 speeds up electron transit at the surface. The results demonstrate that LLNM-M10 exhibits a remarkable electrochemical performance as it retains 183.3 mA h g-1 at 1 C after 250 cycles. More crucially, the modified electrode exhibits an exceptional low-temperature performance of 120.3 mA h g-1 at 0.1 C and -10 °C. Therefore, this presented strategy may provide a new method for further application of Li-rich layered cathode materials.

Composite Nanoarchitectonics with CoS2 Nanoparticles Embedded in Graphene Sheets for an Anode for Lithium-Ion Batteries.

Cobalt sulfides are attractive as intriguing candidates for anodes in Lithium-ion batteries (LIBs) due to their unique chemical and physical properties. In this work, CoS2@rGO (CSG) was synthesized by a hydrothermal method. TEM showed that CoS2 nanoparticles have an average particle size of 40 nm and were uniformly embedded in the surface of rGO. The battery electrode was prepared with this nanocomposite material and the charge and discharge performance was tested. The specific capacity, rate, and cycle stability of the battery were systematically analyzed. In situ XRD was used to study the electrochemical transformation mechanism of the material. The test results shows that the first discharge specific capacity of this nanocomposite reaches 1176.1 mAhg-1, and the specific capacity retention rate is 61.5% after 100 cycles, which was 47.5% higher than that of the pure CoS2 nanomaterial. When the rate changes from 5.0 C to 0.2 C, the charge-discharge specific capacity of the nanocomposite material can almost be restored to the initial capacity. The above results show that the CSG nanocomposites as a lithium-ion battery anode electrode has a high reversible specific capacity, better rate performance, and excellent cycle performance.

Ultrafast Kinetics in a PAN/MgFe2O4 Flexible Free-Standing Anode Induced by Heterojunction and Oxygen Vacancies.

Flexibility and power density are key factors restricting the development of flexible lithium-ion batteries (FLIBs). Interface and defect engineering can modify the intrinsic ion/electron kinetics by regulating the electronic structure. Herein, a polyacrylonitrile/MgFe2O4 (PAN-MFO) electrode with heterojunction and oxygen vacancies was first designed and synthesized as a flexible free-standing anode of FLIBs by electrostatic spinning technology. The PAN carbon nanofiber (PAN-CNF) as the skeleton structure provides fast conductive channels, buffers the volume expansion, and enhances the cycle stability. The heterostructure constructs the internal electric field, facilitates the Li+/charge transfer, intensifies the Li+ adsorption energy, and enhances the interfacial lithium storage. Oxygen vacancies improve the intrinsic conductivity, lower the Li+ diffusion barrier, weaken the Fe-O bonding, and facilitate the conversion reaction. Because of the synergistic effect of the multifunctional structure, the PAN-MFO shows superior cycle and rate performance with ultrafast kinetics. Flexible LiCoO2/PAN-MFO full pouch cells were also assembled that demonstrated a stable cycle performance and power supply in both the plain and bent states.

Change of Consumption Behaviours in the Pandemic of COVID-19: Examining Residents' Consumption Expenditure and Driving Determinants.

This study investigated changes of individuals' consumption behaviours during the COVID-19 pandemic and explored the driving determinants in consumption expenditure in Zhejiang China. Based on the 454 samples of survey data, which were collected in 2020 and 2021, it showed a reduction trend in consumption expenditure during the pandemic. Compared to the consumptions before the pandemic, money spent on housing, food, and beverage did not change too much. However, expenditures on wearing, recreation, and education reduced. Age, family size, and household income were significant to the expenditure changes. Online shopping became an important alternative way for residents during the pandemic and the trend is expected to continue even after the pandemic. Based on the findings, suggestions are summarized as two points. First, the young and single residents are the main group for recovering the consumption for wearing, recreation, education, and public transport. Meanwhile, to improve the satisfactions in online shopping, regulations should be issued by the government in improving the quality of goods and service.

In Situ Gel Polymer Electrolyte with Inhibited Lithium Dendrite Growth and Enhanced Interfacial Stability for Lithium-Metal Batteries.

The practical application of lithium-metal anodes in high-energy-density rechargeable lithium batteries is hindered by the uncontrolled growth of lithium dendrites and limited cycle life. An ether-based gel polymer electrolyte (GPE-H) is developed through in situ polymerization method, which has close contact with the electrode interface. Based on DFT calculations, it was confirmed that the cationic groups produced by polar solvent tris(1,1,1,3,3,3-hexafluoroisopropyl) (HFiP) initiate the ring-opening polymerization of DOL in the battery. As a result, GPE-H achieves considerable ionic conductivity (1.6 × 10-3 S cm-1) at ambient temperature, high lithium-ion transference number (tLi+ > 0.6) and an electrochemical stability window as high as 4.5 V. GPE-H can achieve up to 800 h uniform lithium plating/stripping at a current density of 1.65 mA cm-2 in Li symmetrical batteries. Li-S and LiFePO4 batteries using this GPE-H have long cycle performances at ambient temperature and high Coulomb efficiency (CE > 99.2%). From the above, in situ polymerized GPE-H electrolytes are promising candidates for high-energy-density rechargeable lithium batteries.

A novel strategy for improving performance of lithium-oxygen batteries.

Although the theoretical energy density of lithium-oxygen batteries is extremely high, pulverization of lithium metal anode obviously influences batteries cycling performance. In this work, the cathode was coated with a membrane to protect the lithium anode from moisture attacking and avoid the pulverization. The membrane is composed of polyethylene oxide and poly tetra fluoroethylene, which improves the cycle life of the lithium-oxygen batteries cycles to 230 times, with a limited specific capacity of 1000 mAh·g-1, at a current density of 100 mA·g-1. Furthermore, the batteries perform stable charge and discharge cycles for 55 times in the air atmosphere, with the relative humidity greater than 50%. It demonstrates this strategy provides a new direction for the development of high-performance lithium-oxygen batteries.

Elbaite catalyze peroxymonosulfate for advanced oxidation of organic pollutants: Hydroxyl groups induced generation of reactive oxygen species.

In this work, the abundant, low-cost, innocuous, and chemically stable elbaite (a type of tourmaline) was employed to catalyze peroxymonosulfate (PMS) for wastewater purification by using methylene blue (MB) as one of the target pollutants. The results revealed that PMS could be catalyzed by elbaite within broad pH range (i.e., 2.9-10.7) and with low activation energy (i.e., 18.6 kJ/mol). Complete MB degradation was obtained within 15 min under the optimized conditions: [elbaite]0 = 1.00 g/L, [PMS]0 = 0.50 g/L, initial solution pH = 2.9. MB degradation (%) sustained 99.9 % after five successive catalytic reactions, indicating good durability and long-term stability. In addition, the complete degradation of doxycycline hydrochloride (DOX) and bisphenol A (BPA) further confirmed the degradation activity of the PMS/elbaite system. PMS interacted with elbaite via replacing the surface-bonded and structural OH groups of elbaite with its OH groups to bond with YLiYAlYR and YLiZAlZR cations (R = Al, Li, Fe, Mg, Mn, Cr, V), which offered channels for electron transfer from negatively charged elbaite to PMS, leading to the activation of PMS. Thus, elbaite is found to be promising for catalyzing PMS to treat organic wastewater.

Preparation of low-load Au-Pd alloy decorated carbon fibers binder-free cathode for Li-O2 battery.

Developing high-performance cathode is critical to facilitating the development of lithium-oxygen (Li-O2) batteries. In this work, a low-load (1.32%) Au-Pd alloy decorated carbon fibers binder-free cathode is prepared by facile magnetron sputtering (MS). It is the first use as a cathode material for Li-O2 batteries, and exhibits excellent electrochemical performance. During the second to the 30th cycle of the battery operation at a current density of 100 mA g-1 with a limited specific capacity density of 1000 mAh g-1, the charge and discharge polarization voltage is only about 0.6 V. In addition, the problem of abnormal charge polarization voltage in the first cycle is also investigated. The by-products Li2CO3 are formed during the first discharge, resulting in a significant increase in the charge polarization voltage. The facile preparation method we adopted and our findings may provide new ideas for the future development of Au-Pd alloy composites in Li-O2 or other metal-air batteries.

Synthesis and enhanced photocatalytic performance of 0D/2D CuO/tourmaline composite photocatalysts.

Photocatalysis is considered to be a green and promising technology for transforming organic contaminants into nontoxic products. In this work, a CuO/tourmaline composite with zero-dimensional/two-dimensional (0D/2D) CuO architecture was successfully obtained via a facile hydrothermal process, and its photocatalytic activity was evaluated by the degradation of methylene blue (MB). Surface element valence state and molecular vibration characterization revealed that CuO chemically interacted with tourmaline via Si-O-Cu bonds. The specific surface area of the CuO/tourmaline composite (23.60 m2 g-1) was larger than that of the pristine CuO sample (3.41 m2 g-1). The CuO/tourmaline composite exhibited excellent photocatalytic activity for the degradation of MB, which was ascribed to the increase in the quantity of the adsorption-photoreactive sites and the efficient utilization of the photoinduced charge carriers. This study provides a facile strategy for the construction of 0D/2D CuO structures and the design of tourmaline-based functional composite photocatalysts for the treatment of organic contaminants in water.

Efficient synthesis of Pt-Co nanowires as cathode catalysts for proton exchange membrane fuel cells.

A simple and efficient method was used to prepare highly active and durable carbon-supported ultrathin Pt-Co nanowires (NWs) as oxygen reduction reaction (ORR) catalysts for the cathode in a proton exchange membrane fuel cell (PEMFC). Chromium hexacarbonyl plays a significant role in making Pt and Co form an alloyed NW, which acts as both a reducing agent and a structure directing agent. The nanocrystal exhibits a uniform nanowire morphology with a diameter of 2 nm and a length of 30 nm. In half cell tests, the Pt-Co NWs/C catalyst has a mass activity of 291.4 mA mgPt -1, which is significantly better than commercial Pt/C catalysts with 85.5 mA mgPt -1. And after the accelerated durability test (ADT), Pt-Co NWs/C shows an electrochemically active surface area (ECSA) loss of 19.1% while the loss in the commercial catalyst is 41.8%. Also, the membrane electrode assembly (MEA) was prepared using Pt-Co NWs/C as the cathode catalyst, resulting in a maximum power density of 952 mW cm-2, which is higher than that of Pt/C. These results indicate that the one-dimensional structure of the catalyst prepared herein is favorable to improve the activity and durability, and the application of the catalyst in the MEA is also realized.

Fluorophosphorus derivative forms a beneficial film on both electrodes of high voltage lithium-ion batteries.

Layered lithium-rich oxides, as a series of highly promising cathode material for lithium-ion batteries, attract extensive attention due to their high specific capacity and high working potential (4.6 V vs Li/Li+). However, the poor interface stability of the cathode and electrolyte seriously restricts their practical application. In this article, theoretical calculations, linear sweep voltammetry and cyclic voltammetry results indicate that tris (pentafluorophenyl) phosphine (TPFPP) is a potential dual-functional electrolyte additive to solve interface problems. The TPFPP additive can decompose preferentially on the surface of both electrodes and form uniform and stable protective films, which effectively inhibit the continuous decomposition of the electrolyte and significantly alleviate the dissolution of transition metal ions during cycling. Owing to the above effects, the capacity retention and coulombic efficiency of Li1.17Ni0.25Mn0.58O2 (LLO)/graphite (Gr) cells are improved from 62.6% and 97.7% to 90.6% and 99.8% after 200 cycles at 0.3 C (1 C = 300 mA g-1), respectively. This study provides a wide prospect for the application of lithium-rich materials in the future.

A soluble single atom catalyst promotes lithium polysulfide conversion in lithium sulfur batteries.

CoPcCl is used as a catalytic electrolyte additive for lithium sulfur batteries under the guidance of theoretical calculations. The electrolyte additive strategy is easier to realize and more effective compared with the fabrication of catalytic host materials. Adding CoPcCl in the electrolyte enhanced the sulfur utilization remarkably.